The Chinese authorities recovered one of the black boxes of the stricken China Eastern Airlines plane, and continued the search to find the second box, while new details about the flight pilots were revealed.

An official with the Civil Aviation Administration of China told reporters that search teams on Wednesday found the black box recording conversations in the cockpit, adding that the recordings had been sent to Beijing for analysis.

The plane crashed last Monday in a mountainous area with 132 people on board. No survivors were found, and search work was hampered by heavy rains that fell on southern China on Wednesday and flooded the disaster site.

The plane was on domestic flight MU-5735 from Kunming - the capital of southwest China's Yunnan Province - to Guangzhou on the coast, and it plunged suddenly when it was about to start lowering its altitude in preparation for landing.

Heavy rain hampered research work (Reuters)

Authorities said the pilots did not respond to repeated calls from air traffic controllers during the rapid landing, but it was too early to determine the cause of the crash, which experts say was usually caused by several factors.

According to the information of the specialized aviation website, "Flightradar24", the plane fell vertically towards the ground before it crashed, which is unusual in the opinion of experts.

For their part, the authorities confirmed that the standards of validity and safety were in place on the plane before takeoff and that the three pilots were in good health.

An official in China Eastern said that the pilot of the ill-fated plane, who has worked for the company since January 2018, has an experience of 6,709 flying hours, and his first assistant has 31,769 hours, and the second has 556 hours.

"As far as we know, the three pilots performed well and their family lives were relatively harmonious," the official added.

If all 132 passengers, including 9 crew members, are confirmed to have died, it would be the worst accident in China's aviation sector since 1994, as experts consider the country's overall safety record to be very good.

The Civil Aviation Authority said all the people on board the plane were Chinese.